The present invention relates to a photoresist stripping composition and a process for stripping photoresists, and more particularly, to a stripping composition for removing photoresist films in the production of semiconductor devices and liquid crystal display elements, and a process for stripping photoresist films using the stripping composition.
Semiconductor devices have been produced by the steps of coating an inorganic substrate with a photoresist; patterning the photoresist film by exposure to light and subsequent development; etching exposed region of the inorganic substrate using the patterned photoresist film as a mask to form minute circuits; and removing the patterned photoresist film from the inorganic substrate. Alternatively, after forming minute circuits in the same manner as above, the patterned photoresist film is ashed, and then the remaining resist residues are removed from the inorganic substrate.
Recently, LCD (liquid crystal displays), especially TFT-LCD (thin-film transistor liquid crystal displays) are coming to have a larger substrate size. This leads to various troubles due to nonuniformity in film formation of circuit-forming materials, insulating materials and resist materials as well as due to uneven exposure, development and etching, resulting in increased rate of defective products.
In particular, the nonuniformity in formed films is likely to cause generation of dust due to exfoliation of the formed films during wet-etching, or generation of dust due to resist residues during dry-etching. These dusts are very difficult to remove even by a photoresist stripping solution. In some cases, the dusts remaining not removed causes unsatisfactory bonding of a film formed in subsequent steps. Thus, the nonuniformity in films finally results in increased rate of defective products.
Japanese Patent Applications Laid-Open Nos. 62-49355, 62-95531, 64-981949, 64-81950 and 5-273768 propose to remove photoresist films remaining after dry-etching by photoresist stripping solutions containing amino alcohol. However, these photoresist stripping solutions have no effect on removal of the dusts generated during etching process.
Accordingly, in order to solve the problems, it has been demanded to develop a high-performance photoresist stripping solution which is capable of easily removing resist films, resist residues and dusts generated during etching process, and is highly resistant to corrosion of materials for use in the production of liquid crystal display elements or semiconductor devices.
It is an object of the present invention to provide a photoresist stripping composition which is capable of easily removing photoresist films formed on an inorganic substrate, photoresist residues and dusts generated during etching process in the production of liquid crystal display elements or semiconductor devices, and is highly resistant to corrosion of various semiconductive materials, conductive materials and insulating materials.
As a result of extensive studies to solve the above problems in the prior art, the present inventors have found that a photoresist stripping composition comprising (1) a nitrogen-containing organohydroxyl compound, (2) a specific alkylene glycol monoalkyl ether, (3) a sugar or sugar alcohol, (4) a phosphorus-containing compound and (5) water, completely removes photoresist films, photoresist residues and dusts generated during etching process at low temperatures for a short period of time without causing corrosion of the materials. The present invention has been accomplished based on this finding.
Thus, the present invention provides a photoresist stripping composition comprising (1) a nitrogen-containing organohydroxyl compound, (2) an alkylene glycol monoalkyl ether represented by the general formula: HOxe2x80x94(CpH2pO)qxe2x80x94R wherein R is C1-C4 alkyl, p is 2 or 3, and q is 1, 2 or 3, (3) a sugar or sugar alcohol, (4) a phosphorus-containing compound and (5) water.
The present invention further provides a process for stripping photoresist using the photoresist stripping composition.